Hair Loss After Weight-Loss Surgery: How Common Is It?
HairArticleHair shedding is one of the most common surprises after bariatric surgery. Pooling 41 studies of 7,044 patients, a 2025 review found 47% had hair loss, more after gastric bypass than sleeve surgery. An earlier review found it was more common in younger women and in people with low zinc, folate or ferritin, and that it eased with time. Here is what the studies show and what to check.
In this article
For many people, weight-loss surgery brings a shock in the shower drain a few months later. Here’s what the research says.
How common it is
| Review | Studies and patients | Had hair loss |
|---|---|---|
| 2025 | 41 studies, 7,044 patients | 47%1 |
| 2021 | 18 studies, 2,538 patients | 57%2 |
Which surgery
The 2025 review found hair loss was:1
- More common after gastric bypass than after sleeve surgery
- Most common after duodenal switch
Who’s most affected
The 2021 review found hair loss was more common in younger women, and linked with low zinc, folate (folic acid) and ferritin (stored iron).2 Blood iron and vitamin B12 weren’t linked.2 It also eased with longer follow-up.2
Why it happens
Losing 20 pounds or more and having an operation are both well-known triggers for a temporary shed, usually noticed a few months later.3 Weight-loss surgery does both at once.
Will it grow back?
For a temporary shed, hair usually regains its normal fullness within six to nine months.3 But if the trigger continues, such as an ongoing nutrient shortfall, shedding can last longer.3
What to check
- Take the supplements your surgical team prescribes.
- Ask about zinc, folate and ferritin if shedding is heavy or lasting.2
- Don’t add high-dose supplements on your own; ask your team first.
- Track it with dated photos so you can see when it turns.
See also hair shedding on GLP-1 shots, iron and hair loss after 50 and shedding for more than 6 months.
Try: “I had gastric bypass four months ago and my hair is coming out in handfuls. Could we check my zinc, folate and ferritin, and am I taking the right supplements?”
Hair, Everywhere covers triggers like fast weight loss and surgery in Chapter 5, “The Shed,” in a section called “What Sets It Off.” Its Hair Log notes anything big from the months before a shed, with monthly photos, so you can see the shed start and settle. See the book.
This article is for general educational purposes only and is not medical advice. It isn't a substitute for diagnosis or treatment from a qualified healthcare professional who knows your health history. Follow your surgical team's advice on supplements and blood tests, and don't start high-dose supplements on your own. See your team or a dermatologist if shedding lasts more than about six months, comes in patches, or comes with other symptoms like tiredness or numbness. Girl Playbook does not endorse any specific product, test, or provider.
Girl Playbook sells this book. It provides education and worksheets, not individualized medical care.
Sources
The research behind this article, in the order it’s cited. How we source our articles.
- Obesity Surgery, 2025 review (abstract via PubMed), 2025Hair Loss and Metabolic and Bariatric Surgery: An Updated Systematic Review and Meta-analysis (opens in a new tab)ab
- Obesity Surgery, 2021 review (abstract via PubMed), 2021Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis (opens in a new tab)abcde
- American Academy of Dermatology, 2026Do you have hair loss or hair shedding? (opens in a new tab)abc
Spotted something out of date? Tell us and we’ll check it.
